The specific aim of this proposal is to prepare for publication a book-length manuscript dealing with the history of John Brown's medical system in Europe and the United States. Since completing my Ph.D. dissertation in 1971 on the topic "John Brown's Medical System in Germany During the Years 1790-1806", I have continued to conduct research and gathered materials on the subject of Brunonian medicine in general. My present goal is a much larger and ambitious project concerned with the impact of Brunonianism in various European countries (England, Germany, Italy, France) and the United States. Most of my research is completed, a book outline and chapters planned, and several portions of the work have already been written. A study of Brown's system of medicine appears indispensable for an understanding of late eighteenth-century medicine. Both its theory and practice generated lively and acrimonious debates among contemporary physicians that shed considerable light on the scientific, professional, and social issues of medicine around 1800, especially across national boundaries and differing disease ecologies. I feel that Brunonianism offers unique opportunities for comparative historical studies of medical theory and health delivery at a crucial time when medicine assumed broader responsibilities in society. No similar study has every been attempted. Because of such gaps in historical scholarship, I feel that this work promises to make a significant contribution to our knowledge of late eighteen and early nineteenth-century medicine.